Assessment of Microbial Load Reduction Efficiency of Sewage Treatment Plants (STP’s) in Mysore, Karnataka, India

The present study mainly aims to determine the assessment of microbial load reduction efficiency of sewage treatment plants (STPs) in Mysore, Karnataka, India. The raw and treated wastewater samples were collected and tested for irrigation suitability using irrigation indices compared with the Food and Agriculture Organisation (FAO) standards. Seed germination study was carried and the vigour index was reported to be higher for raw sewage although the seedlings treated with this water had wilting shoot tips. The overall results of the present study observed that most of the parameters of both treated and untreated urban wastewaters have exceeded the FAO irrigation standard and continuous usage of such water may cause detrimental effects on the soil and crops. The sewage treatment plants have also shown very low efficiency in microbial load reduction, and this can have health risk implications to the farmers using this effluent

Fate, transport, and effects of pharmaceuticals and personal care products in urban environment

In the race of technological advancement for better health and better lifestyle, research has founded a strong base to bring out new antibiotics, vaccines, generic medications, and personal care products (PCPs) for the people. On the other hand, the risk and effects concerning residues of pharmaceuticals and personal care products (PPCPs) in the urban environment are a vital challenge to combat. The biotic components of the environment are most vulnerable to the impacts induced by PPCPs. Though the PPCPs are detected in the range of nanograms per liter to micrograms per liter in water, air, and soil, they are potential endocrine disruptors and carcinogens, environmentally persistent, and hostile. Correlations between urban lifestyles, healthcare infrastructures, and PPCPs clearly pose threatening images on the fate, transport, and effects of PPCPs. Hence, this chapter individually focuses on the origin of PPCPs in the environment, the fate and transport of PPCPs in urban environment, and eco-toxicological impacts on aquatic and human genera by providing strong evidence and finally presents the prospective on PPCPs and plausible future trends in urban environments.</p

Source, treatment, and management options of contaminants of emerging concerns (CECs) in water

Contaminants of emerging concern (CECs) are defined as pollutants present in negligible amounts in the environment, which have not been detected previously and cause high-level environmental and health risks. These CECs include pharmaceutical and personal care products, endocrine-disrupting chemicals, persistent organic compounds, disinfection by-products, phthalate compounds, etc. The present chapter reveals the different contamination sources of CECs including point and non-point sources and types of contamination in the context of health and environmental problems. The existing water and wastewater treatment techniques and novel remediation approaches including merits and demerits are discussed in detail. Potential technologies in the treatment of CECs in water and wastewater such as adsorption, advanced oxidation processes, membrane processes, and hybrid techniques are also discussed in the perspective of resilience and implantation. Centralized and de-centralized treatment strategies including novel treatment approaches at point of entry and point of use are well explained with suitable illustration. Safe and sustainable management and treatment approaches including regulatory, citizen science, networking, technological, and other strategies, which have been demonstrated for real-time application, are well elucidated for sustainable management of CECs in different environments.</p

Sonochemical synthesis of graphitic carbon nitride-manganese oxide interfaces for enhanced photocatalytic degradation of tetracycline hydrochloride

The present study focuses on the sonochemical synthesis of graphitic carbon nitride-manganese oxide (GCN/MnO2) nanocomposite for photocatalytic degradation of an environmentally hazardous pharmaceutical compound, tetracycline hydrochloride (TcH). The sonochemical synthesis aided in tailoring the morphology of GCN/MnO2. The characterization results of SEM/FESEM, XRD, FTIR, UV-Vis spectra, EIS, CV, etc., revealed on the morphology, composition, crystallinity, and other photo-electro-intrinsic properties of the materials. The synergy of GCN and MnO(2)results in rapid electron transfer, efficient visible-light absorption, and slower electron-hole pair recombination through its photo-responsive traits against TcH. It was noted that similar to 93% TcH (20 mg L-1) degradation was achieved for 30-mg catalyst dose under light-emitting diode (LED) irradiation (9 W, 220 V) in 135-min duration. The TcH mineralization results were well fit to pseudo-first-order kinetics with a rate constant of 0.02 min(-1)(R-2= 0.994). In addition, the composite possessed fair reusability for consequent cycles. Hence, the as-synthesized composite applied for photocatalysis and photoelectrocatalysis fosters a fit-for-purpose and reliable system in the decontamination of TcH in environmental samples

Degradation of doxycycline antibiotics using lanthanum copper oxide microspheres under simulated sunlight

In this study, lanthanum copper oxide was synthesized under hydrothermal techniques and characterized for doxycycline degradation. The catalyst exhibited enhanced photocatalytic doxycycline degradation under visible light owing to its compatible bandgap energy (1.7 eV). The XRD data revealed high crystallinity of the material with no noticeable impurities. Three-dimensional microspheres of varying sizes (average diameter of 2.52 μm) were observed from SEM. EDX confirms the successful synthesis of La2CuO4. The effect of DC concentration, catalyst dosage, and initial pH on the degradation rate of DC was studied methodically. Interestingly, about 85% of doxycycline (10 mg/L) was degraded within 120 min of light-emitting diode irradiation at pH 10. Oxygen vacancies and surface defects were determined through photoluminescence spectra. The recyclability experiments suggested that the catalyst is capable of degrading DC for three consecutive runs. Radical trapping trials suggested that holes (h+), superoxide radicals (●O2−), and hydroxyl radicals (●OH) are involved in the photodegradation of DC. Herein, the novel approach of La2CuO4 synthesis and the efficient visible-light harvesting capability of as-prepared catalyst reveal the potentiality for DC degradation thereby opening a new horizon of research employing La2CuO4 used for various environmental applications.</p

Visible light responsive AgBiS₂ nanomaterials for photocatalytic applications in removal of antimicrobial compounds and bacterial pathogens: Possible electrochemical pathways

Potential synthesis of ternary chalcogenide nanocomposite to showcase a practical electronic pathway to improve photocatalytic efficiency was carried out. In the present study, AgBiS2 nanorod-shaped with remarkably visible-light absorption was prepared using solvothermal techniques. This material was employed in photocatalytic degradation of amoxicillin (AMX) under visible light irradiation. The results indicated more than 90% degradation of AMX under 60 min having a corresponding bandgap of ∼2.19 eV. In the verge of understanding the photogenerated separation of electron-hole pair, VB and CB potentials were calculated to be 2.06 eV and − 0.76 eV, proposing a possible pathway for the degradation study. The photogenerated intermediates were identified using LC-MS analysis and the mineralization was followed using TOC analysis. A scavenging experiment showed a potential reactive oxygen species involved in the oxidation of organics that proved effective in three consecutive trials.In addition, antibacterial and antibiofilm activity showcased fair efficiency of the material, especially the presence of Ag+ in AgBiS2 improves antimicrobial activity. In case of antibiofim activity, 4 × 107 CFU/mL were seen to be most effective for the biomass formation of the biofilms.</p

Catalysis interfaced multifunctional membranes for sustainable treatment of water and wastewater

The low-level existence of emerging contaminants (ECs) has caused tremendous alarm due to their persistence, chronic toxicity, and endocrine-disrupting impacts on both terrestrial and marine animals. To deal with this issue sophisticated water and wastewater treatment technology are needed. Membrane-based water treatment technologies are rapidly replacing traditional water and wastewater treatment due to their high efficiency, and low price, and can remediate microbial and chemical pollutants from a variety of aquatic sources. state-of-the-art literature on the catalysis of multifunctional membranes has been summarized and critically reviewed. The review emphasizes the significance of improved membrane technology in sustainable water and wastewater treatment applications. It highlights the membrane separation and purification processes, recent membrane technologies, membrane modules and configurations, challenges, and practical difficulties of membrane technology in water and wastewater treatment applications. The major problems associated with membrane fouling in water treatment are discussed and possible solutions through advanced and multifunctional membranes such as catalyst-interfaced membranes, ceramic membranes, carbonaceous membranes, etc. are presented in detail. Also, this review highlights the comparison of different catalytic membranes. To achieve high and potential water flux, improved membrane matrixes and suitable membrane configurations are suggested based on simulation models and configuration techniques.</p